近期不少朋友来信询问能否在新股上市之前参与认购，下面这篇文章是美国证监会对个体投资者参与IPO的说明。概括说来：SEC没有特别规定承销商应该如何配售新股。但是行业通常做法是：热门新股只会配售给机构投资者、满足其设定条件的高端投资者，或者订购其高价服务的客户等。而且通常配售给你的股票不能上市首日就抛售，否则以后不会再给你热门股的机会了，因为承销团一般有稳定股价的义务。- 有钱人才有机会参与！
The underwriters and the company that issues the shares control the IPO process. They have wide latitude in allocating IPO shares. The SEC does not regulate the business decision of how IPO shares are allocated.
While smaller or individual investors are finding it easier to buy IPO shares through online brokerage firms, they may still find it difficult to buy IPO shares for a number of reasons:
The IPOs of all but the smallest of companies are usually offered to the public through an "underwriting syndicate," a group of underwriters who agree to purchase the shares from the issuer and then sell the shares to investors. Only a limited number of broker-dealers are invited into the syndicate as underwriters and some of them may not have individual investors as clients. Moreover, syndicate members themselves do not receive equal allocations of securities for sale to their clients.
The underwriters in consultation with the company decide on the basic terms and structure of the offering well before trading starts, including the percentage of shares going to institutions and to individual investors. Most underwriters target institutional or wealthy investors in IPO distributions. Underwriters believe that institutional and wealthy investors are better able to buy large blocks of IPO shares, assume the financial risk, and hold the investment for the long term.
When an IPO is "hot," appealing to many investors, the demand for the securities far exceeds the supply of shares. The excess demand can only be satisfied once trading in the IPO shares begins. It is unclear how "hot" the offering will be until close to the time when the shares start trading. Since "hot" IPOs are in high demand, underwriters usually offer those shares to their most valued clients.
Underwriting firms that have a high percentage of individual investors as clients are more likely to allocate portions of IPO shares to individuals. Several online brokers offer IPOs, but these firms often have only a small allotment of shares to sell to the public. As a result, individual investors' ability to buy these shares may be limited no matter which firm they do business with.
By their nature, investing in an IPO is a risky and speculative investment. Brokerage firms must consider if the IPO is appropriate for individual investors in light of their income and net worth, investment objectives, other securities holdings, risk tolerance, and other factors. A firm may not sell IPO shares to an individual investor unless it has determined the investment is suitable for that particular investor.
Even if the firm decides that an IPO is an appropriate investment for an individual investor, the brokerage firm may sell the IPO only to selected clients. For example, before you can purchase an IPO, some firms require that you have a minimum cash balance in your account, are an active trader with the firm, or subscribe to one of their more expensive or "premium" services. In addition, some firms impose restrictions on investors who "flip" or sell their IPO shares soon after the first day of trading to make a quick profit. If you flip your IPO shares, your firm may refuse to sell you other IPOs altogether or prevent you from buying an IPO for several months. You can often find these restrictions on the firm's website.
原文：美国证券交易委员会网站 http://www.sec.gov/answers/ipodiff.htm